JVM IR: Avoid direct invokes in callable reference tests

Due to the direct invoke optimization, most callable reference tests
were not generating callable references/lambdas.

compiler/testData/codegen/box/callableReference/function/local/extensionToPrimitive.kt

@@ -1,4 +1,4 @@
 fun box(): String {
     fun Int.is42With(that: Int) = this + 2 * that == 42
-    return if ((Int::is42With)(16, 13)) "OK" else "Fail"
+    return if ((Int::is42With).let { it(16, 13) }) "OK" else "Fail"
 }